Screen device for power sprays and the like



Sept. 24, 1935. H. M. JOHNSTON SCREEN DEVICE FOR POWERSPRAYS AND THE LIKE Filed July 9, 1954 |NVENTOR= HOWARD M. JOHNSTON ATTORNEY.

Patented Sept. 24, 1935 UNlTED STATES SCREEN DEVICE FOR POWER SPRAYS AND THE LIKE Howard Milton Johnston,

Toronto, Ontario,

Canada, assignor to Massey-Harris Company, Limited, Toronto, Ontario, Canada Application July 9, 1934, Serial No. 734,355

3 Claims.

This invention relates to screen devices and more particularly to a device of this character for use in power sprays and the like, the device being located on the inlet end of the hose connection to the pump.

In spraying machines used by fruit and vegetable growers and others there is a container for the spray solution and a pump, the inlet side of which communicates with the interior of the container by means of a hose pipe normally long enough to reach the bottom of the container. On the free end of the hose is a screen device for preventing the admission thereto of unduly large solid particles. There is usually an agitating device within the container to maintain the solids in solution or finely divided suspension.

With heretofore known types of screen devices much diiiiculty is experienced in preventing clogging of the screen which so seriously interferes with eflicient operation of the spraying machine. With some commonly used screen devices the action of the agitator and the suction of the pump directs solid particles into exposed portions of the screen, blocking the latter. When operation is discontinued and particularly when the liquid has been used up these solid particles harden on the screen and have to be manually removed, causing delays and inconvenience.

The object of the present invention is to provide a screen device which will overcome these and other difiiculties, which will be automatically maintained free from solids, which will be washed by the movement of the liquid under the influence of the agitator, and which will be well protected against damage in use.

The invention will now be described with reference to the accompanying drawing in which Figure 1 is a side view of the device partially in section and Figure 2 is a bottom plan View with the base plate partially broken away.

The screen housing consists of a hollow casting having the curved portion l supported upon four legs 2. Centrally disposed in the dome of the casting is an internally threaded orifice 3 for receiving the hose pipe leading to the pump. A circular screen l rests against the shoulder 5 and is strengthened by two bars 6 attached thereto diametrically at right angles to each other. A solid base plate 'I has openings 3 therein to receive the legs 2 and these openings have restricted portions 9 so that by turning the plate with respect to the legs the plate becomes locked within the recesses ill in the legs. A lug H may be provided on the plate to resist circular movement of the latter. A spring member l2 having curved portions 13 for more or less circumferential engagement with portions of the screen and a central straight portion i l for engaging the base plate is located between the plate I and screen 4 to hold the latter in place. The circumferential opening I5 to the screen, located immediately above the base plate, is restricted only by the presence of the legs.

It will be apparent that to disassemble the de- 5 vice it is merely necessary to exert pressure on the base plate adjacent the four legs and rotate the plate to permit it to be removed. The spring l2 and screen 4 are then free.

In operation the screen is substantially horizontally disposed, the legs 2 resting on the bottom of the container. The suction of the pump draws the solution through the screen. Agitation of the solution displaces any solids which might otherwise gather on the screen under the suction of the pump. The disposition of the screen permits any solids thereon, upon discontinuing the pumping action, to fall off or be displaced by abrupt movement of the device, should there be no or insufficient agitation to cause their L entire removal during pumping.

There are thus no accumulations of solids on the screen and discontinuance of pumping ofiers no hazards to renewed operation. The screen is fully protected in the housing and is thus not 2, subject to damage in use.

While the device has been described with particular reference to its use in spray devices it is adapted for use in other connections for which its structure adapts it; 30

I claim:

1. A device of the character described comprising in combination a hollow screen housing with supporting legs thereon, a shoulder within said housing, a screen resting on said shoulder, 35 a base plate removably mounted on said legs providing a circumferential opening to said housing below the screen and a protection for the screen, and a spring member freely supported by said plate and contacting substantial portions of 10 said screen to support it in place against said shoulder.

2. A device as described in claim 1 wherein said -legs have recesses therein and said base plate has openings with restricted portions there- 45 in to receive said legs whereby 'upon rotation the plate becomes locked in said recesses.

3. A device of the character described comprising in combination a hollow screen housing having a threaded outlet and supporting legs there- 50 on, a screen having diametrically disposed reinforcing ribs thereon horizontally arranged within said housing, a base-closing and screen-protecting plate having openings therein to receive said legs removably anchored in recesses in said 55 legs to provide acircumferential opening to said housing, and a spring member having a central portion engaging said plate and lateral portions engaging said screen to support it in place.

. HOWARD MILTON JOHNSTON. 

